Results 71 to 80 of about 36,165 (249)

Dynamical $F(R)$ gravities

, 2012
It is offered that $F(R)-$modified gravities can be considered as nonperturbative quantum effects arising from Einstein gravity. It is assumed that nonperturbative quantum effects gives rise to the fact that the connection becomes incompatible with the ...
Buchbinder I. L., Heisenberg W., VLADIMIR DZHUNUSHALIEV   +2 more
core   +1 more source

Laser‐Driven Charge‐Transfer Dynamics in the Quaterthiophene–Fullerene Donor/Acceptor Interface

ChemPhotoChem, EarlyView.
This ab initio study investigates laser‐induced charge‐transfer in a quaterthiophene/fullerene complex at varying intensities of the external pulse. Pulses above 3 GW cm−2 are needed to trigger charge transfer, which is enabled by vibrations in the donor. Under stronger field intensities, transient effects in the system prevail.
Jannek Räder, Caterina Cocchi, Michele Guerrini   +2 more
wiley   +1 more source

Derivative corrections to the Heisenberg-Euler effective action

Journal of High Energy Physics, 2021
We show that the leading derivative corrections to the Heisenberg-Euler effective action can be determined efficiently from the vacuum polarization tensor evaluated in a homogeneous constant background field.
Felix Karbstein
doaj   +1 more source

Cosmological constant and Euclidean space from nonperturbative quantum torsion

, 2014
Heisenberg's nonperturbative quantization technique is applied to the nonpertrubative quantization of gravity. An infinite set of equations for all Green's functions is obtained. An approximation is considered where: (a) the metric remains as a classical
Heisenberg W., Ivanenko D. D., Vladimir Dzhunushaliev, Wilcox D. C.   +3 more
core   +1 more source

Nonperturbative effects in the proton sea

, 1999
We revisit the evaluation of the pionic mechanism of the $\bar{u}-\bar{d}$-asymmetry in the proton structure function. Our analysis is based on the unitarity relation between contributions of different mechanisms to the inclusive particle production and the total photoabsorption cross-section (i.e. the proton structure function).
Schäfer, W., Speth, J.
openaire   +2 more sources

Programmable Functional Connectivity and Synchronous Activity in Resistive Switching Self‐Assembled Nanostructured Networks

Small Structures, EarlyView.
The adaptive and controllable functional connectivity of self‐assembled nanostructured materials has been investigated by a combined approach based on microthermography and electrical measurements. Interacting active regions and synchronous resistive switching activity characterize the network dynamics at different scales.
Davide Decastri, Thierry Nieus, Cristina Zuccali, Flavio Giacomozzi, Leandro Lorenzelli, Francesca Borghi, Paolo Milani   +6 more
wiley   +1 more source

The S-matrix bootstrap with neural optimizers. Part I. Zero double discontinuity

Journal of High Energy Physics
In this work, we develop machine learning techniques to study nonperturbative scattering amplitudes. We focus on the two-to-two scattering amplitude of identical scalar particles and study a toy model where we set the double discontinuity to zero ...
Mehmet Asım Gümüş, Damien Leflot, Piotr Tourkine, Alexander Zhiboedov   +3 more
doaj   +1 more source

Infrared renormalon contributions in gluon TMD at small-x

Nuclear Physics B, 2020
The nonperturbative uncertainties from the infrared renormalons in the (color dipole) gluon distribution is estimated. It is shown that non-linear saturation effects at small-x shift the first IR pole at the Borel plane from 2/β2 to 1/β2.
Nahid Vasim, Raktim Abir
doaj   +1 more source

Stabilization of 2D Quantum Gravity by branching interactions [PDF]

, 1995
In this paper the stabilization of 2D quantum Gravity by branching interactions is considered. The perturbative expansion and the first nonperturbative term of the stabilized model are the same than the unbounded matrix model which define pure Gravity ...
Alvarez-Gaumé, Ambjørn, Barbón, Brézin, Dabholkar, Das, David, Diego, Douglas, Eynard, Ginsparg, Ginsparg, Greensite, Gross, Gross, Karliner, Klebanov, Korchensky, Korchensky, Marinari, Miramontes, Oscar Diego, Sawada, Sugino   +23 more
core   +3 more sources

Boundary conditions and universal finite‐size scaling for the hierarchical |φ|4$|\varphi |^4$ model in dimensions 4 and higher

Communications on Pure and Applied Mathematics, Volume 78, Issue 10, Page 2001-2118, October 2025.
Abstract We analyse and clarify the finite‐size scaling of the weakly‐coupled hierarchical n$n$‐component |φ|4$|\varphi |^4$ model for all integers n≥1$n \ge 1$ in all dimensions d≥4$d\ge 4$, for both free and periodic boundary conditions. For d>4$d>4$, we prove that for a volume of size Rd$R^{d}$ with periodic boundary conditions the infinite‐volume ...
Emmanuel Michta, Jiwoon Park, Gordon Slade   +2 more
wiley   +1 more source